Can i have with this and can you explain how to do it

How can you find the conditional probability of a given b as the fraction of b’s outcomes that also belong to a, and interpret the answer in terms of the model? i just need a good explanation

Simplify.7x + 3y - 2 + 6x + 1 + y squared 2 you! ; )

Find the magnitude, correct to two decimal places, made by each of the following with positive direction of the x axis a) y= x the answer is 45° but i don’t know how